U.S. Pat. Nos. such as 3,847,867, 3,847,869, 3,850,885, 3,852,242, 3,855,178, etc. describe the general class of polyetherimides of the formula: ##STR1## where a represents a whole number in excess of 1, e.g., 10 to 10,000 or more, the group --O--A&lt; is selected from: ##STR2## R' being hydrogen, lower alkyl or lower alkoxy, preferably the polyetherimide includes the latter --O--A&lt; group where R' is hydrogen such that the polyetherimide is of the formula: ##STR3## and the divalent bonds of the --O--Z--O radical are in the 3,3';3,4';4,3' or the 4,4' position. Z is a member of the class consisting of (1) ##STR4## and (2) divalent organic radicals of the general formula: ##STR5## where X is a member selected from the class consisting of divalent radicals of the formulas, ##STR6## where q is 0 or 1, y is a whole number from 1 to 5, and R is a divalent organic radical selected from the class consisting of (1) aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated derivatives thereof, (2) alkylene radicals and cycloalkylene radicals having from 2-20 carbon atoms, C.sub.(2-8) alkylene terminated polydiorganosiloxane, and (3) divalent radicals included by the formula ##STR7## where Q is a member selected from the class consisting of ##STR8## where x is a whole number from 1 to 5 inclusive.
Particularly preferred polyetherimides include those where --O--A&lt; and Z respectively are: ##STR9## and R is selected from: ##STR10## The polyetherimides where R is metaphenylene are most preferred.
One of the principal drawbacks of the above described polyetherimides is their lack of good fabricability.